Sole marks and other directional structures generally assumed to be of turbidite origin have been found as common features in shallow marine siltstone and shale of Ordovician to Mississippian age in Ohio, Kentucky, and Indiana. The sole marks include: flute casts, load casts, groove casts, current crescents, prod marks, bounce marks, brush marks, and channel casts. Other directional features include: micro-ripple marks, micro-cross lamination, oriented fossils, ripple marks, and cross-bedding.

Comparison of sole-mark orientations with associated cross-bedding directions, shows a high degree of directional similarity. In those fine-grained sequences, where cross-bedding is rare to absent, the ubiquitous sole marks are the only reliable and available indicators of paleocurrent pattern.

This study suggests that paleocurrent investigations of shallow marine sequences need not be restricted to the coarse-grained sediments, since the fine-grained siltstone and silty shale also may have abundant directional features in the form of sole marks.

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